Piston ring



Dec. 25, 17951 Y H p, PHILLUBSA l 2,579,698

PISTON RING Filed Nov. 24, 1947 155 i413 /7 I5 w /4 Patented Dec. n25, 1951 UNITED STATES PATENT OFFICE Prs'roN RING Harold P. Phillips, Hastings, Mich., assigner to Hastings Manufacturing Company, Hastings,

Mich.

3 Claims.

This invention relates to improvements in piston ring assemblies and ring elements therefor.

The main objects of this invention are:

First, to provide a piston ring assembly which is radially flexible and when installed under eX- pansible stress so as to conform closely to irregularities in the shape of the cylinder in which it is installed.

Second, to provide a piston ring assembly having cylinder wall engaging elements which are annula'rly and radially compressible to provide radial spring thrust in all portions of the periphery of the elements regardless of irregularities in the shape of the cylinder within which the ring operates.

. Third, to provide a cylinder wall engaging element having inherent expansibility when installed and on which may be deflected radially at one or more points along its circumference without materially effecting the radially directed spring thrust of the element adjacent to the deflected portions. i

Fourth, to provide a cylinder wall engaging element which may be economically formed of ribbon steel coiled edgewise and when installed, has the desired expanding thrust without the use of expanders.

Fifth, to provide a piston ring assembly of the type described which is particularly well adapted to function as an oil ring in an internal combustion engine to Wipe excess oil from the cylinder walls and direct the oil to return passages in the piston on which the ring is installed.

Other objects and advantages pertaining to the details and economies of my invention will be apparent from a consideration of the following de'- scription and claims.

The drawings, of which there is one sheet, illustrate a preferred form of my piston ring as installed in the piston of an internal combustion engine and four modified forms of cylinder wall engaging elements adaptable for use with my piston ring.

Fig. l is a transverse cross sectional view through the cylinder and piston of an internal combustion engine and along the line I--I in Fig. 2 illustrating my piston ring assembly in operative position.

Fig. 2 is a fragmentary vertical cross sectional view along the line 2 2 in Figs. 1 and 3.

Fig. 3 is an enlarged fragmentary edge elevational view of my piston ring assembly.

Fig. 4 is a fragmentary perspective view of a portion of a cylinder wall engaging element of my invention.

Figs. 5, 6, 'l and 8 are fragmentary-plan views of modified forms of wall engaging elements.

The drawings illustrate a portion of a cylinder block I defining a cylindrical cylinder bore 2 within which a piston 3 is arranged to reciprocate. i

` The piston defines an annular ring groove 4 Within which my piston ring is mounted. Preferably the piston is provided with a plurality of inwardly and downwardly inclined bores 5 (see Fig. 2) through which oil collected from the cylinder wall by the piston ring may be returned to the center of the piston and from there to the crank case ci the engine.

The piston ring assembly illustrated comprises the annular spacer member E and upper and lower wall engaging ring elements 1. The spacer illustrated is that described in my Patent No. 2,404,- 862, issued July 30, 1946, and will therefor not be described in detail herein except to bring out relationship to the cylinder wall contacting ring elements. It is believed to be sufcient to note that the spacer is provided on one side with drain recesses I0 and that the ends are spaced at II. The wall engaging ring elements 'I' are of identical construction so that only one will be described. These ring elements are preferably formed of a flat strip of ribbon steel coiled edgewise, the ring elements being split at I2.

In the preferred embodiment illustrated, the ends of the ring elements are turned axially to provide widened abutments I3 increasing the thrust engaging area between the ends of the ring elements when they are installed in a cylinder under compression and with the ends in abutting relation. v

The ring elements are alternately slotted from the inside and the outside as at I4, the slots exceeding one half the radial width of the ring so as to provide a series of radially bendable peripheral segments connecting the unslotted portions of the ring. A

In installing the assembly on a piston, the lower Wall engaging element I is spread at its split and slipped over the piston and into the ring groove, being in generally circular shape when the abutments I 3 are in engagement. The spacer member 6 is then inserted into the groove with theilanges I3 of the installed ring disposed within one of the recesses I0 of the spacer member. The upper ring element 'I is then installed with its abutment anges disposed in the gap I l of the spacer. Thus, the spacer member holds the wall engaging elements properly spaced axially while the in-l herent resilience of the ring elements urges them outwardly to engagement with the cylinder. lAs

the Wall engaging elements are suiiiciently larger than the cylinder bore when uncompressed in which they are to operate, when installed in the cylinder the ends of the ring elements are in engagement with the result that the spring portions I5 are placed under compressive force'and spring tension.

:Should the cylinder Wall within which the ring is installed have or receive a slightly out-ofround contour due to engine wear, that segment of the ring element functioning in the out-ofround portion of the cylinder will denect outwardly by reason of exing of the bendable portions I5 to maintain the periphery of the element in engagement with the cylinder wall completely therearound. It will be noted that due to the location of the recesses I in the lower face of the spacer ring and the gap II, the outwardly opening slots in one of the ringsV 'i Will be overlapped by the unslotted portions of the other ring 1. Thus continuous sealing engagement is obtained between the cylinder wall and the two ring elements completely around the periphery of the piston.

The modified form of wall engaging ring 1A illustrated in Fig. 5 consists of a flat annular ring of metal preferably formed of ribbon steel coiled edgewise having a series of apertures I6 punched therethrough. Alternate apertures i6 are displaced inwardly and outwardly of the ring 1A so as to form slots or openings IIIA to the inner and outer edges of the ring. The apertures I6 are sufficiently large to cut away over one-half of the radial width of the ring and leave the bending portions ISA opposite each of the slots MA.

The modified form of ring 1B is provided with a series of apertures IBB which are centered vradially within the ring EB so as to leave approximately equal borders on each edge of the ring. The borders of adjacent apertures ISB are cut away or slotted on opposite sides as at I4B to provide segmental edges for the ring with the center of each section having a radially bendable portion ISB of reduced cross section on the opposite side of each aperture from the slot opening thereto. The apertures IBB are of such a size and spacing as to provide circumierentially or tangentially bendable positions I'I of approximately the same Width as the radially bendable portions ISB.

The modified form of ring 'IC illustrated in Fig. 7 consists of a flat annular ring of metal having a series of oppositely arranged triangular apertures IBC punched therein. The apex of each triangular aperture is connected to the adjacent edge of the ring by slots |40, the edges of which are in abutting relationship when the ring isV compressed. That portion of the ring along the base of each triangular aperture forms a radially bendable portion I5C so that the ring can be deflected throughout any portion of its circumference to conform to the shape of the cylinder wall.

The modified form of ring 'ID illustrated in Fig. 8 consists of an annular ring of thin metal in which the radially bendable portions ISD are formed by the oblique slots I4D extending alternately from the inner and outer edges of the ring.

All forms of the cylinder wall engaging rings illustrated provide in eiect a series of separate segmental wall engaging portions along their periphery which are radially bendable in their center and separated by the various types of a constant and uniform radial wall engaging pressure on all portions of a cylinder wall regardless of irregularities in the cylinder wall shape.

The ring elements 1 are desirably formed of ribbon steel of a gage approximating twenty-four one thousandths of an inch in thickness. The thrust abutments I3 are desirable in view of the relative thinness of the stock but with a suitable spacer, satisfactory results can be had without these abutment flanges.

I have not attempted in the accompanying drawing to illustrate clearances and tolerances and I have not attempted to show the parts in their relative proportions. It will be understood that in practice these may vary considerably, depending on the diameter of the ring as well as the axial width of the piston ring groove. The requirement for tolerances and clearances is understood by those skilled in the art.

I have thus described several highly practical forms of my piston ring so that others may reproduce the same or similar rings Ywithout further description.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is: Y

l. A piston ring assembly comprising an annular split spacer member having spaced drain recesses in one side thereof, and a pair of at annular split cylinder wall engaging ring elements positioned one on each side of the spacer member, said ring elements being formed of ribbon steel coiled edgewise and having abutment flanges on their ends, the abutment anges of each ring member retainingly engaging each other under the compressional stress of the ring member when operatively engaging the cylinder wall.. the flanges of one element being positioned in one of said drain recesses and the anges of the other element being disposed Within the gap of the spacer member, the abutting engagement of the end portions of the last mentioned element closing the gap of the spacer element and the flanges thereof retaining said end portions in closing relation to said gap, said ring elements being alternately recessed from the inner and outer edges thereof, the recesses extending over onhalf of the radial Width oi' the ring elements providing springable portions between the recesses where the ring elements are under expanding stress when compressed within a cylinder with the said fianges in abutting relation, said ring elements when the abutment ilanges thereof are in abutting engagement with each other and before compression of the ring elements into a piston ring groove, being of a diameter greater than that of the cylinder wall with which they cooperate.

2. A piston ring assembly comprising an annular split spacer member having spaced drain recesses in one side thereof, and a pair of flat annular split cylinder Wall engaging ring elements positioned one on each side of the spacer member, said ring elements being formed of rib- 5 bon steel coiled edgewise and having axially disposed abutment flanges on their ends, the abutment iianges of each ring member retainingly engaging each other under the compressional stress of the ring member when operatively engaging the cylinder Wall, the ilanges of one element being positioned within the gap of the spacer member, the abutting engagement of the end portions oi' the last mentioned element closing the gap of the spacer element and the flanges thereof retaining said end portions in closing relation to said gap, said ring elements being radially and alternately slotted from the inner and outer edges thereof, the slots extending over one-half of the radial Width of the ring elements providing segmental springable portions bridging the ends of the slots, said ring elements when the abutment flanges thereof are in abutting engagement with each other and before compression of the ring elements into a .piston ring groove, being of a diameter greater than that of the cylinder Wall with which they cooperate.

3. A piston ring assembly comprising an annular split spacer member, and a pair of flat annular split cylinder Wall engaging ring elements positioned one on each side of the spacer member, said ring elements being formed of ribbon steel coiled edgewise, said ring elements being alternately recessed from the inner and outer edges thereof, the recesses extending over one- 6 half of the radial width of the ring elements pro- Viding springable portions between the recesses where the ring elements are under expanding stress When compressed within a cylinder with the ends thereof in abutting relation, said ring elements when the ends thereof are in end abutting engagement and before compression of the ring elements into a piston ring groove, being of a diameter greater than that of the cylinder wall with which they cooperate, said ring element closing the gap of the spacer member.

HAROLD P. PHILLIPS.

REFERENCES CITED 'he following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 1,457,461 Renshaw June 5, 1923 1,881,849 Morton Oct. 11, 1932 2,076,542 Bowers Apr. 13, 1937 2,262,311 Zahodiakin Nov. 11, 1941 2,278,019 Phillips 1 Mar. 31, 1942 2,404,862 Phillips July 30, 1946 FOREIGN PATENTS Number Country Date 123,352 Great Britain Feb. 17, 1919 

